Anatomical Location
The organ is located on the visceral surface of the liver in the gallbladder fossa (fossa vesicae biliaris). This fossa separates the anterior part of the right lobe of the liver from the quadrate lobe.
The surface of the gallbladder facing the liver lacks a peritoneal covering and is connected to the fibrous capsule of the liver. The free surface facing the abdominal cavity is covered by visceral peritoneum. Intraperitoneal variants of the organ with a mesentery are possible.
Organ Structure
The gallbladder has a dark green color, a relatively thin wall, and an elongated pear shape. Its width gradually decreases from the fundus to the neck. Anatomically, it is divided into three parts:
- Fundus (fundus vesicae biliaris / felleae) — the widest and most distal part. It is directed anteriorly and toward the inferior border of the liver, and may sometimes project below it.
- Body (corpus vesicae biliaris / felleae).
- Neck (collum vesicae biliaris / felleae) — the proximal, narrow part. At the junction of the body and neck, there is often a bend, causing the neck to lie at an angle to the body. It is oriented toward the porta hepatis.
The neck continues into the cystic duct (ductus cysticus). The neck and cystic duct lie within the hepatoduodenal ligament (lig. hepatoduodenale). By joining the common hepatic duct, the cystic duct forms the common bile duct (ductus choledochus).
Innervation and Motility
The process of bile excretion and biliary tract motility is termed cholekinesis. Organ function is regulated by the autonomic nervous system:
- Parasympathetic nervous system (visceromotor fibers of the vagus nerve, n. vagus): causes gallbladder contraction and bile ejection.
- Sympathetic nervous system (via $\beta_2$-receptors): causes organ relaxation.
Clinical Significance and Diagnostics
- Duodenal probing (drainage): a method for collecting bile using a tube with a metal olive tip. It allows for the collection of 5 fractions to separately obtain bile from the common bile duct, gallbladder, and intrahepatic ducts. The method is contraindicated in suspected cholelithiasis (gallstone disease), as stimulation of bile flow can provoke stone movement and biliary colic.
- Radiopaque methods: transhepatic percutaneous cholangiography (introducing contrast via a needle through the skin and liver tissue directly into the ducts or gallbladder) and ERCP (retrograde contrast injection through the major duodenal papilla during endoscopy) are used to visualize anatomy.
- Infections and parasitoses: in cholera, the gallbladder becomes acutely distended and filled with colorless, watery bile; vibrios enter it via an ascending route from the intestine. In opisthorchiasis, parasites migrate into the bile ducts and gallbladder due to positive chemotaxis toward bile.
Surgical Procedures (Cholecystectomy)
Removal of the gallbladder can be performed using two main approaches:
- Retrograde cholecystectomy (from the neck): the cystic artery (a. cystica) is isolated and ligated. Then, the cystic duct is isolated and ligated 0.5 cm away from its junction with the common bile duct. Leaving too long a stump risks dilation and stone formation, whereas ligation too close risks narrowing the lumen of the common duct. Intraoperative cholangiography is performed.
- Antegrade cholecystectomy (from the fundus): the peritoneum is incised from the fundus to the neck, the gallbladder is grasped with a clamp, and it is dissected from its bed. It is critical to avoid opening the gallbladder lumen to prevent contaminating the peritoneal cavity. After removal, the liver bed is reperitonealized (serosal edges are sutured together).